iOS Swift 图表：条形图背景色

Question

I create a bar chart that works completely fine. How can I add the bar chart capsule background color? Not want the entire chart background color but I want to need a background color for each bar so it will look like fill and unfill like effet to the bar chat.

    var BAR_WIDTH_CONSTANT: CGFloat = 3
    var BAR_DISTANCE: CGFloat = 14
    var BAR_MAX_HEIGHT: CGFloat = 50
    let MAX_VALUE: CGFloat = 60
    let MIN_VALUE: CGFloat = 0
    var unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0, 4.0]
    var months = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    var graphType = 1
    var maxValue = 30.0

   func setChart(arrX:[String]) {
        let customFormater = BarChartFormatter()
        customFormater.months = self.months
        
        viewChart.xAxis.valueFormatter = customFormater
        self.viewChart.xAxis.labelPosition = XAxis.LabelPosition.bottom
        self.viewChart.setVisibleXRangeMaximum(Double(arrX.count))
        self.viewChart.fitScreen()
        
        var dataEntries = [BarChartDataEntry]()
        
        for i in 0..<months.count {
            let dataEntry = BarChartDataEntry(x: Double(i), y: Double(unitsSold[i]), data: months as AnyObject?)
            dataEntries.append(dataEntry)
        }
        
        let chartDataSet = BarChartDataSet(entries: dataEntries, label: "")
        chartDataSet.valueTextColor = .clear
        
        chartDataSet.valueFont = themeFont(size: 9, fontname: .Poppins_Black)
        
        
        chartDataSet.colors = [.appThemeColor, UIColor(named: "DarkGreen")!]
        
        //Remove 0 value from graphs
        let noZeroFormatter = NumberFormatter()
        noZeroFormatter.zeroSymbol = ""
        chartDataSet.valueFormatter = DefaultValueFormatter(formatter: noZeroFormatter)
        
        chartDataSet.barShadowColor = .clear
        let chartData = BarChartData(dataSet: chartDataSet)
        
        chartData.barWidth = 0.6
        
//        if graphType == 1 || graphType == 3  {
//            chartData.barWidth = 0.4
//        }
        
        viewChart.data = chartData
        viewChart.animate(xAxisDuration: 1, yAxisDuration: 1, easingOption: .linear)
    }

func setupChart() {
    viewChart.delegate = self
    viewChart.chartDescription.enabled = false
    viewChart.dragEnabled = true
    viewChart.doubleTapToZoomEnabled = false
    viewChart.pinchZoomEnabled = false
    viewChart.xAxis.valueFormatter = self
    viewChart.legend.enabled = false
    viewChart.setScaleEnabled(false)
    viewChart.isUserInteractionEnabled = false
    
    let leftAxisFormatter = NumberFormatter()
    leftAxisFormatter.maximumFractionDigits = 0
    
    let xAxis = viewChart.xAxis
    xAxis.drawGridLinesEnabled = true
    xAxis.labelPosition = .topInside
    xAxis.labelRotationAngle = 0
    xAxis.labelFont = themeFont(size: 12, fontname: .Poppins_Light)
    xAxis.labelTextColor = .darkGray
    
    xAxis.granularity = 1
    
    xAxis.axisLineWidth = 0
    xAxis.labelCount = 12
    xAxis.granularityEnabled = true
    xAxis.valueFormatter = self
    xAxis.labelRotationAngle = 0
    xAxis.gridColor = .clear

    let yAxis = viewChart.leftAxis
    yAxis.drawGridLinesEnabled = false
    yAxis.axisMinimum = 0
    yAxis.axisMaximum = Double(maxValue)
    yAxis.axisLineWidth = 0
    yAxis.labelTextColor = .clear
    yAxis.drawLabelsEnabled = true
    yAxis.labelPosition = .outsideChart
  
    let dAxis = viewChart.rightAxis
    dAxis.drawGridLinesEnabled = false
    dAxis.axisMinimum = 0
    dAxis.axisLineWidth = 0
    dAxis.labelTextColor = .clear
    dAxis.drawLabelsEnabled = true
    dAxis.labelPosition = .outsideChart
}

This is what I'm looking for.

This is what I have done yet.

Answer 1

if you are drwaing your BarChart using Charts, then to apply corner 
radius you should have to change the internal code of the Charts 
Framework.

You can do it as:
Search for the BarChartRenderer.swift file and replace the (every)line

context.fill(barRect)

with the code below

let bezierPath = UIBezierPath(roundedRect: barRect, cornerRadius: 3.0)
context.addPath(bezierPath.cgPath)
context.drawPath(using: .fill)